This invention relates to fiber reinforced concrete, and, more specifically, to a method of mixing fiber reinforced concrete without the formation of fiber balls therein and to a package designed for use with the method.
The desirability of employing fibrous reinforcing material in concrete has been known for a number of years. In many instances, the use of fiber reinforcing material eliminates the need for reinforcing rods in that fiber reinforced concrete can have the strength of rod reinforced concrete and can be formed at lesser cost. Where the concrete is used in roadways or the like, the presence of the fibers at the exposed surface to the roadway also provides improved wear resistance.
One perplexing difficulty that has stymied extensive use of fiber reinforced concrete is the tendency of the fibers to adhere to each other and form balls which are not fully wetted by the concrete mix itself. As a result, there is a poor concrete to fiber bond and a corresponding decrease in strength. Moreover, where the balls are of significant size, a partial void results to form a flaw or weak spot.
One solution to the problem is the use of specially designed fiber feeders for separating fiber balls found in a package of fibers and slowly feeding individual fibers into a mixer or the like. One type of feeder of the type mentioned is obtainable from the National Concrete Machinery Company Division of Irl Daffin Associates.
Such a feeder works well for its intended purpose, but is large, cumbersome and expensive. As a consequence, it does not readily lend itself to use with small concrete mixing systems. Moreover, the cost of such a feeder can discourage its use in large concrete mixing systems.